Layered Silicon Nitride-Based Composites with Discontinuous Boron Nitride Interlayers |
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| Authors: | Zoltán Len&#;é&#; Kiyoshi Hirao Manuel E Brito Motohiro Toriyama Shuzo Kanzaki |
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| Affiliation: | Synergy Ceramics Laboratory, Fine Ceramics Research Association, Nagoya 462, Japan;National Industrial Research Institute of Nagoya, Nagoya 462, Japan |
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| Abstract: | The influence of a strong/weak interface ratio on the mechanical properties of Si3N4/BN-based layered composites was studied. The ratio was controlled by the number of BN spots between the adjacent Si3N4 layers. By increasing the BN interface area from 0% to 72%, fracture toughness increased from 7.7 to 10.9 MPa·m1/2, and bending strength decreased from 1275 to 982 MPa. Fracture toughness was improved from 8.6 to 10.1 MPa·m1/2 by additional heat treatment of samples containing 2 vol%β-Si3N4 seed particles. The bending strength of samples with 35% weak BN interfaces, measured perpendicular and parallel to layer alignment, was 1260 and 1240 MPa, respectively. This confirmed the two-directional isotropy of layered samples. |
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| Keywords: | layered ceramics boron nitride silicon nitride |
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